I use 4' sections of fiberglass military masts. The military really uses them for tent poles, but they work pretty well for 4-5 sections. When I had the SMB I would bungie them to the top and bottom of the ladder for a very solid 2m antenna mast. Attach a 2m yagi and you are in business. I do the same thing now with my jeep for public service events when I am in fringe areas. Below is a photo of the mast but it doesn't show the yagi mounted on top.
You can pick up the masts on ebay, but they are usually cheaper at hamfests and swaps.
They make a metal ring collar at the top to attach guy ropes to. I have used them when going above 25'. They also make a fiberglass ground base. (Can't recommend that though.)
Also, if you are interested, our Ham club is doing its annual mini-dx event in July (12-14). Its a 3-day (low-key social) operating event on the Mattole river (Humboldt County) Its great if you want to get some exposure to working portable HF. Let me know if you are interested.