That's great that you are looking to get into outdoor roller skating.
To answer some of your questions:
Almost any skate "boot" will work fine for outdoor recreational skating. Tall, short, vinyl, leather - it's just up to your preference. The only essential consideration is that it should fit you properly. Better materials will last longer and will break in nicely over time, but a good quality boot is not the most important factor for outdoor skating.
In general, tall boots (because of their higher heel) make balancing a bit easier for many beginners, as they position your weight more forward, over your toes. The two main advantages of short-style boots are greater ankle flexibility and a more powerful stride.
This is one of the most important factors in deciding on a roller skate. There are lots of great wheels on the market these days, for outdoor skating.
For a beginner skater, I would suggest that you don't want too big of a wheel - bigger wheels are FASTER and make it hard to get your feet under you. We usually suggest the SureGrip Aerobics, the Radar Zens or the Kryptonic 65mm for beginner skaters.
Plates & Bearings
Oh boy. This is a big world with lots of ins and outs. And you can spend a bundle very easily. You have to really assess your commitment to roller skating here.
Cheap plates will not make your skating experience fun, but very good plates are very expensive. In general, you want to avoid plates/skates made by Chicago, Pacer or Roller Derby. Brands made by Riedell, Sure-Grip and Dominion are fairly safe bets. For bearings, those made by Powell/Bones are never a bad choice.
Buying in a store vs. buying online
Because I work for RollerGirl.ca (which is an online store as well as a brick-and-mortar store), I clearly have a bit of a bias, but here are a few tips, being as objective as I can:
- The question of sizing is obviously an important one. If you buy in-store, you know your sizing is good. If you buy online (particularly if you are overseas), you would do well to buy from a store who knows how to size skates. Once you have an idea of which skates you are interested in, call or email a couple shops to see how they would size you, and that should give you a pretty good idea about fit.
- Buying online gives you MUCH greater selection compared with any given real-live-shop. Most shops can special order items for you, but this may be more expensive or take a long while.
- Be aware of pricing. There is higher overhead associated with retail shops compared with online stores - the prices may be higher in some stores.
Phew! I hope this helps. Please keep posting if you come up with more questions