It was nice of your friend to give you speakers, but the 702e on Hifishark are selling for only £60 to £80, which gives you an idea of their value. With a £1000 budget the speakers will be the weakest link in the chain, and just about anyone here will tell you that speaker choice is the most important thing. I would sell them and add the money to your budget and start fresh. You might get £100 for all 3 if in good condition.
The Denon DRA800H looks to be pretty decent. 100W per channel which is a good place to start unless you want concert level music. Whether that is enough power depends upon the efficiency rating of the speakers (the higher efficiency the less amplifier power you need). That model has a subwoofer pre-out which is also good as it allows you to add a powered subwoofer later if you want good deep bass.
That's a lot of money for a CD transport. Are you set on buying new? You could save money looking at the used market and put more towards the speakers. The Denon DCD600NE is CD only. No SuperAudioCD or DVD audio support so no ability to play multi-channel audio in the future if you ever decide to go with surround set. It's a nice unit that matches the amp, but perhaps not the best bang for the dollar.
Denon makes nice turntables. I'm not familiar with that model, but it's fully automatic, belt drive and a nice table to start with. Since you're in Eurpope, consider Project as well. Hopefully it comes with a good cartridge. Project turntables at that level come with the Ortofon 2M red which is nice.
For cassettes you'll likely have to look at the used market. We have a thread in the forums "Are these finds good deals?" where people can get opinions on used finds. Not sure what will be available in the UK. For cassettes it will be hit and miss.
Having given all that consideration, are you ok with selling the Missions and if so what budget is left for speakers? Maybe forgo the cassette and/or turntable for now and get really nice speakers and add components later. Speakers tend to be a long term investment (except for some of the members here
![Big Grin :D :D](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
) so take your time choosing them.