Try your local irrigation supply, plumbing supply, or big-box home improvement. I think the small brush you're referring to may be a plumber's brush used for cleaning copper prior to soldering (at least that's what we use for cleaning metal threads).
Other things you'll find handy are PVC compression couplings and tees, 2 pipe wrenches (14 in.), a pair of slip-joint pliers ("water pumps") and pipe dope (teflon tape or paste).
A lot of old systems around here are also galvanized - we convert to PVC when and wherever possible, using male or female adapters or compression.

I find a dental pick type of tool, commonly available at hardware or hobby stores, is great for cleaning out nozzles and heads.

the tools you need are inthe tools aisles at your local home improvement store. you need 2 monkey wrenches, one to hold the pipe and one to turn the connector. any wire brush will do, and then a regular crescent wrench for the brass.

unless you plan on cutting and putting threads on the pipe, the pipe threader would be better to rent as needed. i have one at home that does from 1/2" up to 1 1/4", but the ONLY reason i have it is that it was given to me. i have never used it in the 4 years i had it.