Shell and Sleeping Platform; Is 300 lbs Too Much Weight?

Planning on buying a Tacoma Access Cab TRD Off Road 4x4 in the next few weeks. One of the first priorities will be to put on a shell (probably ARE) and bulid a sleeping platform in the back. Total weight will be +/- 300 lbs. Based on all the suspension issues that the Tacoma's seem to have, will I have an issue with this ammount of weight? Will I need to upgrade the suspension, or will the existing suspension (with or without the TSB) be good enough? Also, if I do need an upgrade, what would you suggest?

Thanks in advance for your help.