Might be worth a look at this deal too. If the code works, it's an extra battery and 3ah for £10 extra. https://www.hotukdeals.com/deals/dewalt-dcd796m2-gb-18v-li-ion-brushless-combi-drill-2-x-40ah-16998-with-code-at-toolstation-3491320
There appears to be more stock now...
The 290 pack consists of the highest end older models now. Their replacements would the DCD996 combi and the DCF887 driver. You can get the DCD 796 and the DCF887 usually in a kit together for around the £250 mark when on offer. The 887 driver is better spec than the 885. It has 3 preset torque settings which I think Is very useful. A driver is in and around £70 and a 4ah battery around £50. The 985 combi is better than the 796 mostly and it has big torque numbers 80nm I believe. I would probably prefer the 796 and 887 driver personally as a set. But the set you posted would also be very good. Any Drill combi north of and including the DCD778 will be plenty suffice for general masonry work DIY and most pros. Really the higher 996 etc is for things like reinforced concrete conditions etc. Anything heavier than 13 to 15mm and you need the bigger SDS drills.
Oh yeah, sorry I must have been led to a different drill when looking on YouTube at reviews
No dont worry! I think it's great that people are doing this sort of thing. Once it's all up and built it will be a great achievement then it gets addictive building stuff. Yes the chuck is the front bit that tightens down on the drill bit. Metal is harder wearing and some times if the plastic gets damaged for example it can feel rough which is why I believe people prefer the metal chuck but for most its negligible.