You can convert its easy But why would you want a pick up?
You could sell your r top sides and doora on ebay but they dont fetch alot at the moment (picked on up for my 88" for £20)
Easy Mod, Bear in mind normally for a 88 inch landy you would need a "Spacer plate" On the 109 you don't need this plate, Although if you get one thrown in its worth Keeping as they are becoming rarer by the day!
piece o **** to do and seen as 109 truck cabs are few and far between yer making yer landy a little bit select. the spacer plate is a bit of bent tin that fits between the truckcab and the rear bulkhead on an 88 so i wouldnt dwindle on it fer too long, yer wint need one. you can normally get a truckcab fer a tenner off fleabay. the roofs are normally battered but they straighten out with a rubber mallet and it all adds to the character. oh and by the way, yer hard top is worth **** all so you would be better off weighing it in
Before you get rid of your hard top let me know as i have a 109 van body and i fancy one with windows.
You may also want to consider running both ie a Hard top / truck cab in winter and a rag top / no top in the summer.
Running a landy with no top in the sun is so much fun and you get a lot of looks.