K.S.
I don't think gas ovens come in convection.
We had a single oven that was original to the house and a stand alone microwave. The oven went out, so I was hoping to convert to a gas oven since there was a gas line in the place. Apparently, gas wall ovens are hard to find, too, because we ended up with an electric double oven (oven and microwave) instead.
We went to a dent and scratch place and got a terrific deal. We did consider a convection oven, but that would have meant having a double oven that was a regular oven and a convection with no microwave. Our space was also a 24" wide space, which limits the choices.
The salesperson spoke highly of the convection oven, but we didn't need two ovens at this time and the price for a convection oven was significantly more especially when you considered the cost of installation on top of that.
As it turned out, we learned that our original-to-the-house oven was wired to a 110 circuit for the last 40+ years, which the electrician told us was never up to code. We had to have a new 220 circuit run through the wall and a new circuit added to the breaker box. To install the line,he had to cut out a swath of drywall and drill through each stud to the breakerbox. We have a vaulted ceiling and he could find no easy access through the ceiling space to run the wire safely. So we ended up with an additional $600 in expenses for the electrician and for the drywall repair.
It has been my experience in 25 years of homeownership that any home repair or upgrade will cost you at least half again as much as you think it will originally, so make sure you build that into your budget if you are working on a budget.