Instrument equipment selection

I?ve decided to use the Vans supplied panel and do a basic day/night VFR panel just to get in the air. Later I?ll build a whole new Garmin G3X panel including auto pilot. Right now I have some older GRT screens, a Gtx 327 transponder and the engine components for the GRT EIS 4000. I'm under the class B and will also have to spring for at least ADSB out.

Including the components I already have, I?m thinking for a Com the Garmin GTR 200B which has a built in intercom, the ACK A30.5 altitude encoder, and really no idea what the cheapest route is for ADSB. I would like to have ?In? capability if cost will allow but would really like to have any components that could transfer over to be compatible with the G3X someday. For a GPS I?m looking at the aera 660 mounted to the panel with the sky geek mount.

Other than that my electrical system will be basic similar to the one offered by the good folks at B and C, seen here.
https://bandc.com/wp-content/uploads/2018/05/001-510_vfr_single_alt.pdf

Any and all input would be appreciated. Again I?m just trying to get a cost conscious panel built and get a couple of kids through college and this 11 year project in the air soon. Thanks!

These days, so much depends on other stuff; you need to think, now, about the panel you eventually want. For example, your cheapest route to ADSB may be to buy a UAT and gps position source from GRT or other vendors, for about $1500, and for now display traffic on an iPad (you didn?t say what ?old? grt efis you have, it may or may not display traffic). BUT, that UAT will most likely not display traffic on a G3X, if that?s your ultimate goal. So you can either buy an iPad and G3X compatible UAT now (more expensive), or plan on a different ifr route that can use the low cost UAT?s (e.g., GRT). Likewise, if you ultimately plan on a GTN TSO?d gps, you won?t need the gps position source for the UAT. But that?s later, not now. So everything depends on everything else. Do a lot of thinking, now.