Just got back from work,the weekend starts now!
Firstly,there are various alternators and power steering pumps for your car,you will need the O.E numbers off the old one to match it correctly.
Prices for new alternators vary from £143 to £296 (exc.VAT)
prices for the P/S pump vary from £220 to £280 (exc VAT)
The book time to change the alternator is 1.2 hours,and the time to change the P/S pump is 1.2 hours also.(The prices you sourced yourself sound very reasonable,but make sure they are the correct items)
On top of this you'll need an auxillary belt (around £25 to £30) and a top up of power steering fluid.
As for the cambelt,book time is 3.6 hours.I didn't get any prices for the parts as some parts needed to this job properly are Renault only.You'll need a Cambelt kit,New crankshaft pulley bolt and 2 rear cam seals.Who ever you decide to entrust with the job MUST have the Timing pin locking set for this engine.The bottom cambelt pulley isn't key wayed on to the crank,and if you don't have the locking kit it can all go pear shaped.(I have personal experience of this.......!!!
).You MUST also ensure that a new pulley bolt is fitted.If you reuse the old one and this comes loose,you will have a rearrangement of internal parts within the engine!
Hope this helps,and good luck!