Those bolts I'd imagine are probably for a bar inside the wing that connects the 2 mounts, keeping it rigid though I may be wrong.
Mounts can't be bought separate, the rubber pieces that sit between the spoiler and the bootlid and all the other little mounting bits can be.
More collage did a wing like the 32R wing that sits a little bit higher, the outer bits don't touch the bootlid.
Veilside also did a similar one with a bit more of an aggressive look to it
Tomei did a nice looking high wing but might not be your cup of tea.
Lots of other Jap companies also did/do GTR copy wings that look the same but are made of FRP so should be a fair bit lighter.(East Bear, West Yokohama, Charge Speed etc.)