Doh Time for a new alt!
Anyway, for Slugys: I would suggest you put a few in advanced robotics and improved armor repair, add an erp (look under engineering on the market) and some repair tunings. As a blue pilot it's not too difficult to reach a point where you can repair 2 damage for 1 ap on small repairers. With the correct erp you can then run as many repairers as you need to, permanently. Today I was running 3 to farm blue bots since they put out quite a bit of damage. I wouldn't suggest hitting blue bots though, go for green. Hardeners don't work very well in such a setup, since they actually cost ap to run, unlike the repairers*. They'll be useful again once you get into a mesmer or kain mk2, since once you have 3 repairers running, the hardener provides more benefit to your armor bar than another repairer would. As your extensions improve it is actually possible to reach a point where you can run medium repairers like this too, at least as blue. Not sure for the others, but it's doubtful. Fitting tool tells me that one day I'll be able to repair about 3-3.5k of any type of damage every second without touching my accumulator Oh, and don't use medium guns on small targets. Ignore the bot bonus.
If you prefer to use the assault, throw on 5 guns, a repairer, maybe a sensor amp or two, and any weapon tunings you can fit. Then just try to keep too many of them from locking you at once. You'll kill faster but spend more time running around, locking targets, repairing and recharging. It's probably more efficient since you'll save a bit on ammo costs. Although you lose some of the fun factor when people walk past and pause for a moment to watch you tanking a whole spawn.
With high enough fitting skills you can farm tank style in an assault too. You'll still lose some damage from fitting repairer tunings instead of weapon tunings (although if you needed sensor amps when kiting you're not losing anything here since you don't need them for tanking), but less than you lose in the mech. There's also less room for repairers, but it won't be a big deal if you're farming targets with weak damage against you.
*Hardeners can be useful if you're super lazy like me, as a sort of 'half repairer'. If the mobs aren't putting out enough damage to keep your accumulator high enough to permanently run a second or third repairer, but they're outdamaging the first one or two repairers, swapping that second or third repairer for a hardener may even it out so you don't have to bother turning that repper on and off according to your current needs. You can just leave the first repper (or two) and the hardener running permanently.