If you want black, it is BEST to order the jacket and vest at the same time. There are MANY shades of black and a bad match can look REALLY bad.
However, you MAY get lucky and find ones that work GREAT together.

In all seriousness, I'd look into tweeds, hunter green, & navy, as well as black (for those particular tartans).
Green is more "bold" for today, but I am planning on making myself one.

In vests, you can either match/coordinate EITHER the jacket or the kilt.
Tweeds are considered "coordinating" for most tartans.

For cheep vests, look at thrift stores. The main difficulty is matching ANYTHING, as the retailer and fabric's mill is essentially TOTALLY unknown.