I am not an expert by any means but I have been skating for fitness for several years. I have quite a few pairs of inline skates from K2, Rollerblade and Bont. My recommendation for outdoor fitness skating would be the Rollerblade Tempest 100/110 or for a little more performance the BONT semi-race. Both are higher cuffs than pure racing skates and perform great on the open road. K2 has the Radical and Radical pro series with a higher cuff and softer boots. They are a good skate as well but offer less support.
The BONT is essentially a modified race skate whereas the RB and K2 were designed for fitness from scratch.
They all come with top notch wheels and bearings.
I can not help you with choosing an "agressive" skate as I do not do that myself.
I think you should get two pairs. As you noted, aggressive skates have very small wheels, which do well for grinds. But for fitness skating, you'll be much happier on larger wheels. If you haven't skated the big wheels before start with 90s.(4x90mm). I don't know how you feel about protective gear, but I would recommend wearing lots of it while you are getting back into the sport. You'll be going faster on the big wheels and speed increases the chance of injury.
Robert has made a good point. The RB Tempest 100/110 might be too big a wheel to start back with. Though I went from a 76 to a 100 mm wheel rather easily. I trade off between 80 and 100 mm now depending on what skate I am in the mood to wear.
The skates I recommended come in a 90 mm size wheel. However if you think you will adapt quickly you may want to get the larger wheel model and simply switch out the wheels to 90 mms until you are comfortable and then when you are ready you can move back up to the 100 mms. You can't do that if you buy skates with 90 mm wheels as the frames usually will not allow upsizing.
Ahh yes. The Bont Alpha is a very good skate as well. The smaller wheels are easier climbing hills. I believe the boot is similar to the semi-race but less heat moldable. I considered that skate. I buy my skates used. The Apache were my first pair purchased new. I have the semi-race because they became available on E-Bay. I never saw a pair of the Alpha.
I occasionally skate on a pair of RB lightening (5 wheel 80 mm). Much easier to manuever on hills and corners but slower on the straights. Still I like to change up sometimes if nothing else just to remind me of how much equipment has changed.
I like the Bont ALPHA with 90 mm wheels . I am a trailblader and the 90 mm work better on hilly trails with the Bont brake . I have tried all the rec. skates and never knew what skating was until I upgraded to these.
I love aggressive skating! It is completely different than other forms... I am assuming you have never done it from your post, in which case, I dont suggest buying two skates on that budget bc then you will get just two subpar skates... if you can spend that much on two skates-go for it! lol
If you want to buy just one good skate, this is how you do it: make sure your frame can fit a wheel up to 90. Yes the bigger the wheel the longer/better the roll but it is absolutely not advisable if you want to try aggressive skating! Having a frame that can fit at least that will be just fine to fitness skate. I am both a speed and an aggressive skater, and I use 90's when i fitness skate bc I LOVE to jump curbs, do spins, fun turns, etc... the bigger wheel makes you higher off the ground and forces you into a long frame which doesnt do well for those of us who like to play on our skates :)
For grinding... someone on 110s could grind as long as they have a grind plate! When looking for a skate, get one with a grind plate and side planks on the boot. You can switch out your wheels to 72's for aggressive and bump up to 90s for fitness...
Skating the ramps is so fun! Dont get discouraged when you feel overwhelmed- just be confident!
BTW, switching wheels and bearings its easiest to just have two separate sets! lol TruRev is having a sale on ABEC 7's and wheel's.... www.trurev.com
Or thinking now about it.... get the urban or aggressive skate and just make sure you can remove the frame! When you want to do fitness you can just switch out the frame! A little more complicated, but then you get the exact frame you want and probably much better quality if you go with a speed skate company... I suggest marking the place of the frame on the boot with a sharpy once you find the sweet spot :)