For the radio there are a lot of things to consider. For example, your budget, do you have or plan on having lots of R/C models and want affordable receivers, or do you care more about all out performance? It sounds like you're interested in telemetry, which I can appreciate, I just don't find it particularly useful on a race car. I do use some telemetry features on non-race vehicles like bashers and crawlers. It's nice to monitor motor/esc temperature and voltage of the batteries for example. For racing, ESC telemetry is probably more valuable for review after runs if anything.

I think weighing the categories should help you decide which radio will be best for you. I personally chose to have multiple transmitters because I have a lot of vehicles. For example, I have a Sanwa M17 for my race cars. The Sanwa receivers are crazy expensive, so I only have a few. I also have a Traxxas TQi w/bluetooth module for any Traxxas vehicles, and the aforementioned Spektrum DX5C for Losi and ARRMA rigs. Both required a minimal cost and I get to simply bind a new vehicle from those brands without having to spend extra money on additional receivers. However, for all of my remaining R/Cs I use a RadioLink RC8X. It is packed with features, has a premium feel, very inexpensive receivers, and a giant model memory capacity.

I haven't personally used the G7P, but it looks like it would be a very good budget option based off of reviews. I do have the FlySky GT5, and for a pretty basic radio, it works great. Just avoid the FS-BS6 receivers. The less expensive (non-gyro equipped) FS-A3 performs much better.

TLDR; the best alternative radios I can suggest that I have direct experience with, that sounds like they might be in your target budget, are the RadioLink RC4GS, or RC6GS. Both radios offer minor telemetry function that doesn't require proprietary connectors/software, 30+ model memory, full featured adjustments (e.g. end point, exponential, sub-trim etc), and have a wide array of supported receivers that are very affordable. I've been wanting to try the Radiomaster MT12, but it looks like it has quite a learning curve. Some great but more pricey options include the FlySky Noble, and the RadioLink RC8X. Without going down the massive rabbit hole of going super hardcore with racing, for a servo I would recommend the Savox SC-1252MGP or the AGFRC B44BLS v2. Both are fast, light, small, and plenty strong. There are likely less expensive as well as WAY more expensive servos, but these are two that I've used with success.

Note: While the RCXGS v3 transmitters don't have a premium feel, if you later decided to upgrade to the RC8X, the receivers are still compatible.