Having operated a few too many times on this engine here is what I would recommend. Pull the heads and see what you have. Everything is very well written up in Rave. Disconnect the exhaust and remove the head with the manifold on - it will be easier. Don't worry about timing tools just yet, yes you will need them, but first you need to know what you have.
The M62 block is robust but when it goes bad it is done. Taking off the heads will tell you if you have any block damage. If the block is bad you need a new engine. Either way the head has to come off so it is not like you are going to waste your efforts unless the engine block is bad.
I advise this course so you don't waste money on parts you will not need. You can do all this work with the engine still in the car - it is not too bad if you have the space to pile up all the parts you are going to pull off.
Once you verify the block is good then figure you need new timing guides, water pump, hoses, chains, gaskets .... In the USA figure about $1,000.00-$1,250.00 if you include rebuilding your vanos plus having your heads milled.
The last engine I installed in my 2004 L322 was bought with a blown head gasket. Nothing tough on these engines to work on, but you need to pay attention and you need the timing tools.
As for coils, buy used until you have it all sorted out. Locally in the USA they are pretty cheap - I have a box of extras I can give you if you are in Minnesota any time soon.