Well, it depends on what features you want. Most switches have 2 or 4 SFP/GBIC slots. You need 5, so depending on your bankroll, you could start with a used WS-C3508G-XL-EN from ebay for $100,- over a used WS-C3550-12G and up to one of those 3560E with 12 SFP slots, but I guess that's overkill as everything else beyond the 3560E (4500 etc) as well. Maybe there is something in the Cisco Small Business series available, too. The 3508 is reaaaally old, be aware of that, just mentioned what's possible ;-)
Let us know what features you need, maybe we find something that fits better.
Kr, uebi
PS: This was my first post :-)