I decided to stick to 49mm filter lenses (small) with my OM and I really like the three I have: 35mm f2.8, 50mm f1.8 (also have a 50 f1.4 but prefer the 1.8) and the 100 f2.8. The 100 is amazingly small and particularly wonderful. I think you'd have a hard time finding a smaller 3 lens set in an SLR (and pretty inexpensive!). I think the 24mm f2.8 would be next on my list.