Connecting Solid State Relays To AC Heating Elements - Is this circuit correct?
Your new circuit (2nd diagram) should work just fine.

You need to calculate how much power the SSRs will be dissipating.  Assume that there is a 1 Vac drop across each SSR.  Because you didn't mention in your question how much current the oven is supposed to draw, we can't estimate how much heat you need to get rid of.

You may also want to put a SSR or relay on the convection fan.