Danny,
firstly welcome to the forum!
Next the simple answer is YES you can build a buggy from your ford, you will find it easier if you can find a pre-built chassis that just needs the engine mounts changing to mount your engine / change hubs / brakes etc, possibly one of the blitzworld chassis's could be modified to suit your engine and running gear. the other option is to build from scratch (which is what I did) there are a few things to consider before going this route -
1 - It will take you longer to build as you will need to adapt and change things along the way (no matter how well you design it)
2 - You need to spend A LOT of time designing the buggy end to end preferably on some kind of engineering design software (CAD/CAM) the software isn't vital but it makes life easier!! to ensure the chassis is safe your suspension design works and everything fits into the frame, its a very steep learning curve when designing your own vehicle, the maths alone required to setup your suspension and work out the correct spring rates will make your eyes water!! (But its worth it)
3 - You need to be able to fabricate - so your going to need additional tools - things like a TUBE bender (NOT a PIPE bender there is a difference), a Good MIG welder, Possibly a TIG welder (Or a mate that has one and knows how to use it), cutting forming and shaping tools, several angle grinders (so you can have cutting and grinding/flap disks ready to hand all the time) and the usual amount of spanners hammers etc etc but most importantly you need to know how to use them all SAFELY!!
4 - You need space to build it! (Applies to both options but more so if your building from scratch)- You can build it in a single garage (Like I did) but when you get to a rolling chassis stage your going to have to roll it out to work on it - which means the weather needs to be ok (its not good to MIG in the rain ;D )
5 - You build it and design it using the IVA rules book to ensure all your designs will pass the test - this should not be considered a draw back, a lot of early kit cars / buggys wont pass the new IVA test as they were originally designed, so building a vehicle whilst all the time considering the rules is a wise choice, even if you purchase an old or new chassis you will need to make changes to get it through its test (so dont think the bought chassis is plain sailing)
6 - Sometimes you will look at it and think you will never finish it - You will, dont listen to the idiots that tell you you cant build a car from scratch in your garage and put it on the road! - and NEVER EVER be tempted to take short cuts and bodge it, you will regret it and it will probably be picked up in the test.
And most of all (and this apply's to both routes) Enjoy it - its supposed to be fun - frustrating as it can be at times, once you turn that key and pull out onto the road for the first time, its simply awesome, and you will forget all about the long nights, scraped knuckles, and being told off for putting engine parts in the dish washer!!!!
Hope that helps :
:
Rich