The first thing you should do is make sure your SRX is towable four down.  Not all vehicles can be towed.  Read your owners manual to be sure.  Then check the weight of your SRX.  Make sure it does not weigh more than your motorhome is designed to tow.  Then research and find the tow equipment that suits your needs.  I like the Blue Ox base plate because it is well hidden on my dingy,  I like my Blue Ox tow bar because it stays on my motorhome rather than my dingy when it is not being used.   I use a SMI stay in play braking system, but it would seem that a braking system built into the tow bar would be much less expensive.  And I don't mean to imply that other tow equipment is not as good, I just happen to like Blue Ox.

We use a Roadmaster Falcon 2 tow bar with an Even Brake supplemental brake system. Primary reason is because it came with our first used motorhome and it was a tried and true system for me as a novice dinghy tower.  Remember that the tow bar and supplemental brake systems also have weight restrictions so you want to be sure you are evaluating the entire system of RV, tow gear, and toad when selecting.

You might also want to consider joining Family Motor Coach Association (FMCA) as they publish a lot of research and a number of guides about towing with a RV including how to select the right equipment. They also publish a towables guide by year that will let you look up your toad and see what it weighs, towing restrictions, etc. It does vary by vehicle year. In my experience most RVs are rated to tow in increments of 5000 lbs and a 2016 SRX sits in the low to mid 4000's. Your tow weight has to include all the add ons that get stuffed in or on the toad like fuel, bikes, kayaks, etc so be sure to include your planned uses in your calculations.