Rivetting Fuel Sender?

[skov]

I've got an ali fuel tank and a universal fuel sender and I'm wondering how I should mate the two together.
I was going to drill and tap some holes in the tank and use screws to hold the sender on, but I'm not sure the walls of the tank are thick enough.
Is there any reason I can't/shouldn't rivet just the sender on instead?

Whilst I'm at it, the sender came with a rubber gasket - should I be using any sealant in addition to that?