1. Do I need an DC charger?
All chargers are DC actually. Some just have and AC/DC supply built in. I would recommend getting a DC power supply. That makes finding a charger much easier (and cheaper). You can use a cheap computer power supply if you want. I have one from geeks.com that is rated over 20A and it was $15 on sale. It is built really cheap though
and I have not got it going yet.
2. What are some good chargers to look at in the 130 range?
ICE comes to mind... most other good chargers I can think of will cost at least a little more. ($160-200 range)
3. Can I use True RC 8000 mah packs if they're 10-15c?
Yep... for all but the most extreme uses.
4. Do I need a balancer?
Not really, but it's recomended. You can check the voltages manually (to see if they are out of balance)... and even balance them manually(by charging/discharging the each cell individually). But a balancer is much easier, IF you have a pack that needs balancing.
5. Can I bash with these?
Sure
5. How can I make a batt tray? Where can I buy one if I can't get materials?
Velcro straps like the Gorilla straps that rcmonster sells... and maybe side guards made from simple aluminum angle.