The overflow kits that require you to drill the side of the tank are usually not too risky to use. If you go to Home Despot and buy a piece of glass for a few bucks, you can practice drilling holes... there isn't much to it once you understand the basic concept.
As long as the tank you are drilling has suitably thick glass (most anything 55g or over will not have a problem), and you know it's not tempered, you shouldn't have any issues unless you use too much drilling pressure or you overtighten the bulkhead nut... by a lot.
Regardless, as far as the lift pump goes... since I run several of these overflows, I keep a handful of them on hand. I've had them last a few weeks, but I've also had them last over a year. The thing is, when they go, you are in a world of hurt if you don't have a spare, and they are nearly impossible to find locally. It's best to always have one new in box, on hand, then order another immediately when you have to break into the spare.
A few places sell these little "filters" that you can put on the line to protect the pump, but they leak something bad, and they cost only a bit less than a new pump, so replacing the pump is far easier and more reliable.