When deciding your storage solution the TPS isn’t what’s important. The IO load, and the cache hit ratio are what matters. If you are running 10000 TPS and 100% of your data will be in cache, then it doesn’t matter. If you are running 2 TPS and 1% of data will be in cache then you need the fastest storage solution possible.
iSCSI runs over standard Ethernet which is probably running at 1 Gig per second. Fibre runs over either 4 Gig or 8 Gig links. You can get 10 Gig NICs for your iSCSI, but you’ll need 10 Gig switches and your storage will need 10 Gig iSCSI ports. You’ll also need to enable Jumbo Frames on all the equipment.
Without more information a proper recommendation can’t be made.