Well, if you've only a small lot, 25 hectares or less, then perhaps something smaller will meet your needs, and probably be easier on your pocket too !

• Basic Vehicle

• Needs to be 4x4 - whether that be a tractor, dumper, quad or a modified road going 4x4 will be dictated by additional considerations.  Two wheeled drive machines have limited use.
• Must have good treads - worn tractor/dumper tyres (aka slicks !) are of little use unless at Silverstone !
• A winch is essential !  Either the vehicle needs to be fitted with one or you need a portable device (e.g. Tirfor)  - the vehicle will get stuck at some point, vehicle recovery without the right kit is time-consuming, tiresome, stressful & potentially expensive !
• Needs to be diesel, in which case it may be suitable to be run on red-diesel (tax free, at little over a pound a gallon !), but check with the engine manufacturer first.  Also, unless it's classified as an agricultural vehicle, or a mobile crane, it mustn't venture onto the Queens highways !

• Additional Kit
• Winch - You'll need one of some form or other if you're going to even think about timber harvesting (coppicing excepted)
• Hand Operated
• Tirfor - expensive, available in various ratings.
• Ratchet Type - suitable for short pulls, but not for vertical use.
• Powered - Drum (i.e. cable is stored & winds onto a drum)
• Electric winch - if 12V vehicle mounted, only suitable for occasional use.  Despite their phenomenal cost they have an extremely low design life as they are designed for vehicle recovery.
• Direct drive - the classic forestry winch
• Hydraulic - more flexible with regards to mounting
• Trailer/Forwarder
• Needs to be self powered (via. PTO from pulling vehicle) otherwise it will soon bog down the pulling vehicle.

• Conversion Machinery
• Sawbench - Circular or Band
• Thickness/planer
• Covered woodstore - but once you've all the above you can easily make one can't you ?

See here for a possible design - would need slatted sides.