LPG protection?

I am considering buying a 1990 H plate Rangie for some offroad fun and have a question regarding it's LPG conversion. The twin 65L LPG tanks are underneath the body and I wondered about underbody protection. Can anybody recommend something?
Also the perenial problem of the tailgate 'may need' repair and the headlining 'maybe' sagging. Any ideas about repair costs and availability?.

All comments gratefully received as will have to haggle hard to get it in my budget.

Hi.
Personally i would go for a two inch lift kit. What style of off roading do you go for, is it the " gentle approach " or the very amusing for the spectator foot to the floor, oops there go the lpg tank's approach. In all the time i've been off roading there was not much i could'nt get through on road bias tyres, side steps and a bit o' thought. (Much to the disbalief of Mr V. Cobleys son) If you've not been over the pass from the Happy Valley Near Aberdovey go, it's bloomin great, but don't take the p38 cus i don't think it'll fit all the way. (Unless you go really fast that is !)
With regard to the rooflining i bought a two piece headlining from MXM 4X4 in Worcester 3 or so years ago for about £120 and it was superb. The guy who bought JFK off me helped me put it in.
Sorry i never had to touch the tailgate. But they do a grp replacement for £295, (bottom) andm metal top for £270.25 with tinted glass with Vat inc (i just looked in nerding monthly). Lift kit is £231.00 inc vat.

Hope that helps.
Cheers Nick.