What about the best Gpu’s Rig parts with a budget to 8.000€? And the best Pool?

Good morning, even if inexperienced I would like to start a new activity as a miner, especially Monero and Litecoin as I have a friend who, even if he is fasting in the specific sector, is a computer technician by profession and therefore could provide the various assemblies and settings. I have a budget of 7-8.000 € and I would like to have some opinions on which configuration could be particularly performing as a productivity ratio Hash / sec. I specify that I have rejected the idea of Asics for their non-existent ductility, while with a Rig, by changing the internal software, I can choose what to undermine. I would also be interested to know which are the most serious and reliable online pools. Thanks in advance to those who will give me some advice.