Dual purpose bike rack - seeking recommendations.

Another thought, put a front mount hitch receiver on the Burb. Helps return some of the weight to the front axle and it's easy to get the bikes on and off. Only downside we've found is it can make it hard to get in and out of parking lots with very steep approaches. Then you can use whatever 2" equipped rack you want to use (probably don't want to go smaller if you're putting 4 adult sized bikes on it unless you've got very light bikes).