anyone recommend a 10g baset sfp sx for Dell switch

You've got a mix of terminology there - do you mean a gigabit SFP 1000Base-SX, or a 10 gig SFP+ 10GBase-SR ?

I've mostly used HP switches with HP transceivers - lifetime warranty and no finger-pointing when something doesn't work (in fact third-party devices don't work in newer HP or Cisco kit so you have to buy their parts unless you find a supplier who can program the ID to be convincing enough to fool the the switch).