Hi and welcome! You have come to the right place but be aware that we are all individuals with differing preferences so, do seek advice but ultimately it's you that has to be happy with your first purchase so take your time and do your homework before buying.
As said, the Tiger 1 is a good choice as there are several manufacturers making them and in several types and equipment spec levels. There are endless upgrades and mods available too BUT there is one very important thing to remember. Right now the top manufacturers are uping their game by providing more and more electronic features so you really will miss out if you don't buy the very latest versions (beware of sales lit claiming it's s latest version - often it's not!). The latest versions are no more expensive.
For real value, the new Henglong Tiger 1 with version 6.0 electronics will not disappoint, especially when it can be purchased from UK eBay sellers for under £90 delivered.
You then move to Taigen / Torro examples which are more expensive but include metal upgraded parts in various levels. Forgebear is your UK supplier here.
Next is the BB or IR debate. For me the gun flash and barrel recoil is a great touch of realism and by ability to IR battle is great fun but beware that each manufacturer has their own IR standards. Custom upgrade boards can overcome this but are not cheap.
Hope this all helps. Remember, take your time, do lots of research and get it right first time
