I thought you can have 7 implants with 7 endurance so it would look like this.
There are 9 implants in total, the 7 implants comment was referring to 5 SPECIAL implants and the other 2 general ones - the Damage Threshold implant and the Health Regeneration implant. You can of course mix and match to get the ones you think are important or just put Endurance at 9 and take them all.
Where would I even get the caps for these implants?
Play the game? The build I gave plus all the implants is a goal to shoot for regarding your SPECIAL stats and abilities, not something you should expect to have by level 3 or something. Loot items from fallen enemies, complete quests and get paid to do it, gamble in the casinos and clean them out, play caravan, fight in the Thorn... and many other methods for making money or collecting items you can sell for caps. Honestly, by the mid to late stages of the game you should be swimming in caps with nothing to spend them on even after you've purchased all the implants you want.