Baja Beast Crower Cam for 350

[Chromeblvd]

First off: 89 Chevy Suburban 4x4 on 35's...(possible) blown head gasket on a 180k 350 TBI motor. I was pulling my work-truck home one day last summer. It was an hour drive. My work truck weighed 15,000 lbs. and there were plenty-o-hills. Pulled infront of my home...large cloud of smoke engulfs the neighborhood. Low water in radiator...ouch! Temperature guage was still at normal operating temps.
Second: money is tight...new hobby, business, taxes, high heating bills, gas, etc.
Questions: When I perform a compression test and it tells me the head gasket is the culprit...can I just replace the gaskets and still rely on the vehicle for long drives? Of-course this is specifically for this scenario. I understand there are many what-if's at this point. Since the truck temporarily smokes of oil on start up and the number 8 plug is oily, replacing the valve stem seals should resolve that problem. Correct?
Initial Question: Would it be a bad idea due to high mileage and not replacing other initial components like bearings and crankshaft to add a torque cam like the Crower-Baja Beast cam and hydraulic lifters? I am being told by many backyard mechanics, like myself, that I should completely go through the motor if I were to add the new cam. Today, I was told by a professional mechanic, one who installs these cams on a regular basis, that I wouldn't need to do anything else to the motor other than replace the timing chain. I've driven his work before and this cam will give this 350 the oomph it needs. I plan on using this vehicle as a tow vehicle for my hobby. At the most, it'll pull 2,000 lbs boat/trailer for 4-10 hours once a month. Does anybody agree/disagree with what I've said? Should I stick with the gasket rebuild kit and forget the cam for now and wait on a new motor? Or do both for under $250 parts and my labor?