Re: Hardtail upgrade replacement
Yes, the Gotoh GTC101 should be a direct replacement, and has a cosmo/smoked chrome option. They also offer different saddles (i.e. brass or steel). As mentioned above, sometimes changing just the saddles can make a considerable difference. Ultimately, it depends on what you're looking for sonically.
A number of manufacturers have measurement specs on their website, so you can check against what you have stock.
Regarding Hipshot, I presume you're thinking of the Ibby HM, which does indeed look nice.
For hardtail, I personally love the Schaller Hannes, but this requires woodworking to install and is not often offered stock on guitars. Lovely piece of kit, looks like a Batmobile component.