If it helps I use the Sprint 5 seats in my play car. They are a true suspension seat with a tube frame like any other suspension seat on the market. They also fit in real tight areas because they do not take up to much space.
I am sure the TEC seat would be a great choice and the reason for the lower price is because they are made out of fiberglass. If you have any questions send me an email with your number and I will call you firstname.lastname@example.org . We are a Sparco distributor and give an RDC racer discount. If you are going to buy Sparco go through us or UPR.