Sue, my favorite shrub that stays relatively short and blooms all the time is plumbago. It also responds really well to pruning if it does get taller than you want, but it probably won't. It has what I'd refer to as a 'relaxed' habit meaning it tends to cascade or sprawl.
Plumbago (Plumbago auriculata)
A hummingbird magnet is Red Firespike which will do fine in that condition as well, but you'll be pruning it all the time because it tends to get taller than you want.
Firespike (Odontonema tubaeforme)
