Wuf,
Take heed to all the replies here pal. The guys know what they are talking about.
I don't want to read about you in the yearly Darwin Awards. To win here, you have to DIE!
A problem with a regular bosun chair is, that many can't get you high enough to work atop the mast. You end up working with your arms overhead. I have a Top Climber chair that I can take myself up & have my head above the masthead. But even with this, I have someone work a safety halyard.
I sometimes use a local mobile rigging guy that works charging a fair price. I didn't feel like going thru the trouble & replacing my 3 foot antenna an Osprey took out. He came, went up & the whole job costs me $75.00. He was done in ten minutes.
You may want to check into using a rigger. A $60.00 power winch, the pain of installing this, that not-so-safe platform, this has Darwin Award written all over it. I cannot believe the power winch has the capacity for lifting say, a 200# man & all for only $60.00?
I thought smaller power winches are designed to lift sails, not people.
ps: be careful of what you buy at Harbor Freight. Simple tools etc. for light duty are fine but, I wouldn't trust my life to a product from China. Hell they can't make a drywall product without poisoning it first.
CR