I can't comment on these vendors except to say that you should make certain of two things:
1: tax is included in price. Lots of time tax is not included in the posted price, also some other hadnling fees.
UT prices include ALL tax (which is substantial) and free shipping. They also come with a photocopy of the code numbers onthe back, which you need if the tickets also get lost. They also give you a refund if the bag they arrive in is unopened (or at least they used to have this policy,I think they still do)- all policies I like.
2: Make sure you are not signing up for a vacation club tour.
If the Hilton you are looking at is downtown - then downtown Orlando is pretty far from WDW. Not to mention that if you try to go to WDW in the morning, there's a good deal of traffic. Orlando is a good size city. Disney is technically in Lake Buena Vista. I don't know the downtown Hilton specifically. Bonney Creek is located basically inside WDW property - though not on WDW property (there was once parcel of land that Disney didn't buy up.)