A couple of thoughts on this topic, commercial brokers hate delayed commissions. The theory is that their work is done up front and its the LL job to figure out the risk. Also, while brokers don't participate in the downside (tenant leaves early) they also don't participate in the upside such as if a tenant is a huge success and becomes the next Starbucks or something and your property becomes a lot more valuable. Industry standard here in Southern California is 50% of the commission is paid on lease execution and 50% upon tenant opening or commencing rent. You will have a tough time finding a good broker that will agree to something different.
Believe it or not, LL's investing in tenants is much more common today in retail. With consumers (especially in LA) preferring the mom and pops over the national chains, some of the most successful retail developments have substantial LL investment. This can take the form of a tenant improvement allowance or an actual equity position in the company. That said, do you want to be in the LL business or the restaurant (or whatever) business? Maybe both.
Also, it is very common to get a % rent clause in retail if you are investing or providing a substantial TIA. That way if the tenant is crushing it, you will participate in some of the upside.
I would love to hear more about the project. I'm available anytime for free advice, and I promise I won't try to sell you on CBRE.