I was in the kind of same situation, bought my current Defender to take to Morocco. So I will list what I did to prepare mine
Where ever possible I use genuine LR parts or parts marked OEM, as a rule don't buy cheap pattern parts, as you don't want stuff failing out in the sand pit.
New discs, pads and callipers
4 Timken wheel bearings
4 shocks and HD front springs, new rear Land Rover shocks failed soon after returning to the UK, now replaced with Bilstein Gas shocks and rear helper springs
New AP clutch and Ashcroft dual mass flywheel
Stainless straight pipe and cat delete, remap, EGR blanking kit
Silicon intercooler hoses, as rubber ones breakdown and collapse internally with the oil residue that flows through them
New radiator and intercooler, fuel filter and both oil filters
New fluids, brake, clutch, coolant, diffs, transfer box and gearbox
Front and rear diff guard, now have a fuel tank guard fitted too, as the standard one is made from tissue paper thin steel
HD front bumper and winch, unnecessary for Morocco
6 Cooper Discoverer STT tires and quality steel modular wheels, never needed the two spares though
Roof consul to install the CB
Stupidly expensive Ring lightbar, never used it in Morocco
Removed rear seats and made plywood platform to install the 240v Waeco fridge running off a 1400w inverter, which fed from a leisure battery being charged by a electronic split charger.
New chrystal wipac headlights with night breaker bulbs
4 new UJ's, now have new diffs and transfer box as the truck has 100k on it.
4 HD drive flanges
2 Ashcroft rear drive shafts
You don't need lifted truck or a modified one really for Morocco, all you need to do is go through your Defender front to back mechanically, I have a full service history on mine, but some of the parts were looking just a little old, so I swapped them out, you may not have to, what I did really was my personal preference.
You will need though, tip top suspension and steering, as that takes a proper battering for 9 hours a day, dont really need expensive parts, just good quality items. This includes all bushes, radius arms, panhard rod etc
Check your swivel seals on the front axle, don't want too much grease leaking from them as the dust and sand will start eating the already leaking seal and eat away at your swivel balls and CV joints.
Cooling system, needs to be bang on, day one, you will find yourself hammering for hours on motorways across France and Spain, or depending on your route, maybe just Spain, for hours and hours. Then the cooling system is subjected to high temps whilst crawling through deep sand and rock trails in Morocco for 10-15 days, so its needs to be looked at, as does the water pump, thermostat and hose condition, anything feeling sticky or soft, change it, as remember, you've still got to hammer it for hours back north across Spain and possibly France to get home.
Swivel bearings need checking,drive flanges and seals, but probably the most important thing to have is quality tires.
A serviced Defender can trundle around with no worries, I probably went overboard, but that's just me, I like to look after my toys,as I find selling them easy once I'm bored with them.
You don't need a roof tent, most kip in cheap pop up tents, or in the back of their Landys, some sort of camping stove and camping stuff, water carriers, jerry cans, tools, stuff like that is needed to live out of your Landy for the best part of three weeks, oh a proper fridge is a most excellent civilised addition, cold beers, well until they run out on day 5, then its frozen cokes, rock hard bread that needs thawing, is a nice thing to have in the middle of nowhere.
Cost wise, roughly from memory
Ferry return from Portsmouth to Santandar, £700, or you can bore yourself to death and save £200 each way maybe driving through France and pay the tolls.
Ferry return from Tarifa Spain to Tanger Med, £180
Morocco insurance for a month £65
Cash wise, I guess I spent, £1500 on top of the above, but I did go nuts in the ferry bar from Spain which is silly money.
I would say £2500 covers everything, I may be way off, Ken is the master of saving cash, he can advise better.