Diff oils, transfer box & gearbox fluids are always worth renewing.
General things like checking condition of pads, disks, anti freeze, etc
As for the lift, you've got a few options open to you depending on budget?
1.If you want the "money's no issue" approach then the Calmini kit's a good one but you won't see much change out of a £1000 at the current exchange rate.
2.f you've a smaller budget but still willing to spend the £300 ish it would cost for the OME Springs & shocks are always good quality.
3. Cheaper option is to buy extended shocks from some where like BloodRed 4x4, think there about £130 + shocks which could be bought from dave at Llama 4x4
4. Or cheapest option is the spring spacers at about £60 for a pair + shocks if want ?
Loads of advice on here and quite literally hundreds of people with lifts that range from mild to wild

Just do a quick search on suspension lifts and there will be enough results to keep you reading for the rest of the day
