I'd think with the PA speakers you'd generally want a sub, but may depend on your extension goals. I'd look used to keep the price down and if the cabinets aren't in the best condition, just wouldn't really matter out in the garage that much I'd think. I found a pair of JBL 4311Bs a while back, they're my L/R speakers in my garage/workshop, mounted up high (upside down, tho, to keep tweets nearer ear height also angled down slightly) on shelving that works out great for needed positions (7.3 system overall, tho I could definitely be happy without the subs, but since I've already got several....)