Spend as much as you can afford on the initial purchase. Buy cheap and you may find you are spending much more than 5k to get it right unless you are lucky. Lots of good advice on buying cars on here. Be patient. There are a few nasty examples around..
Here s mine with the charge speed rear bumper (tweaked for my ARK Grip) with side skirts to match. Supplied and fitted by the best body shop on here (in my oinion) RT Performance. They will make supply and fit the chargespeed for you...
I am a good friend of the above so wouldn't disagree with him as it all about opinions. When I had mine fitted by RT I was speaking to Taras. He had an ARK on his 350z and has fitted others and just gave me his advice not do it as it changed the exhaust note which is superb as is. Just my opinion but not saying its a NO NO. Would try it without first personally.
Not running on spacers but I am running on Tein S Springs which once settled drop you about 20mm. Running on 19 inch Rota GTRs and have a mines front lip. No issues with speed bumps etc.
Welcome. As above. Don't buy the first one you see unless it ticks all the boxes. Patience pays dividends in the long run. Plenty of advice and help available here..