The actual spannering takes only 2-3 hours but you will have to wait overnight for gasket sealant to go off before bolting everything up.
We were a little taken aback at the price of solder these days. Eleven quid for a small reel of 1mm resin core. Ridiculous. A genuine head gasket for the TDR was £30. Genuine base gaskets are £16 each while pattern ones are a more reasonable £3.50. A genuine head gasket is a good idea. Pattern base gaskets are perfectly adequate.