There's a patch/performance list for the MC-808 on the Roland site. Under the product manuals section on the Roland site you'll find that the MC-808 has (3) documents. The first is the manual, the second is the patch/performance list, and the third is the midi data list. Click on the patch/performance list.
If you like the patch list on the 307 the 808 should make you drool all over yourself. Plus the 808 has 128 note poly, and "indepth" patch editing. Like the Fantom Xa, the MC-808's sound engine can have up to 4 voices per patch, and you can tweek the crap out of them!
The 808 will work for trance, techno, ect. The 808 is designed for "electronica".., meaning--tehcno, dance, trance, DnB, Euro, Rap, Hip Hop, R&B, and so on.
The Fantom Xa will chop samples like you saw in the video for the MC-808. That's why I suggested the Xa over the Juno-G. The Juno-G's audio recorder won't chop samples like that.
Yes all this can be done via software too, but software can also get very expensive. Once you start with a basic software set-up you're gonna want more, more, more more. You'll eventually want more softsynth, effects plug-ins, VST's and the whole shabang! That gets costly. You'll also have to keep up to date on your computers hardware. If you start driving a lot of audio on you computer the magic word is RAM RAM RAM and MORE RAM
I hope it works out for ya.
Squeak