This charger is a bit more than you wanted to spend, but it will also handle 2/3C lipo to future proof you a bit:
http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXCYJH&P=7
I have an older version of it that doesn't do lipo and I use it to charge my glow heater 1,2,4,8 x AA packs, receiver packs, 8 cells in my transmitter (with a proper plug) and even at one point in time, my dewalt screwdriver and B&D drill (which were both replaced with lipo version so I have to use the device specific charger now). Mine is supposed to do .2-5A, but on AC, it only goes up to 4.5A. The newer one says it will do 6A, so maybe it will at least do up to 5A which should be plenty to charge your stick pack. I used mine for that as well when I used the ez-start and roto-start. I eventually just converted everything to pull-start so I didn't have to carry a starter around. Anyway, the MRC charger does a nice job topping the batteries off without cooking them. And, if your not pressed for time, you can always drop the current so it doesn't strain the packs. Only downside is I have to adjust the current every time I turn it on. Once on, it retains the setting after adjusting it so I don't have to switch again when charging another pack.
As for your upgrading the rockers, it's not a bad idea. I've broken 5 or 6 over the years, front and rear. However, I never broke one when I had a slayer, only on my revos. I upgraded to aluminum, but it was a total pain in the ass. All I could find the last time I bought were integy and when I bought for my other revo, I also bought integy. In both cases, the recess for the bearings isn't deep enough and causes it to bind when you tighten down the screw. I spent over an hour on each stupid pivot with my dremel trying my best to carefully deepen the bearing seat. By the time I was done, my hands were shot and I swore to never again buy integy when fitment may be an issue.
However, if you can find some 4x6mm shims... and your only option is integy, get the shims so you can effectively make the post taller and not have to grind anything like I did. May not be a bad idea regardless what brand you buy to get some shims.