Based on the questions, you are just beginning to learn the basics. I'm sure it seems to be overwhelming to you.
Start simple. Forget quad band radios and antennas. You will learn why, once you begin gaining experience. Start with a simple 2/70cm, 50 Watt mobile radio like a Yaesu FT-8800 or a Kenwood TM-V71A and a decent dual band VHF/UHF antenna like a Comet SBB5 (with an appropriate mount). A radio with a detachable face panel is a LOT easier to install in a vehicle.
This is a typical mobile setup. Radio brands and models may vary as well as antennas.
Usually an antenna mount comes with a coax, long enough to reach most radio installations in a typical vehicle. Usually a mount will include a 6ft piece of RG-58 coax. It's all you need. You can use the same cable and connectors as on your CB radio. A better quality coax will be required if it's longer than about 20 feet to minimize losses but you don't need t worry about it for a mobile installation.
Usually you don't need an inline SWR meter for VHF/UHF radios. You may need to borrow an antenna analyzer to check your antenna and possibly trim it to center on a specific portion of the band, if needed. You set it once and forget it. Usually a decent antenna will cover the whole band with an acceptable SWR.
A CB SWR meter will not work well on the VHF/UHF bands.
I'm not sure how you can grow into an antenna. If you grow, you will most likely get bored with VHF/UHF very quickly and decide to get on HF. IMHO, HF bands is where the real fun is. This will open a whole new dimension to you. You will have access to world-wide communication at your fingertips, in your vehicle too. A 100 Watt HF rig like a Yeasu FT-891a (or similar) coupled with a Tarheel "screwdriver" type antenna is one of the best combinations for mobile HF. You will routinely talk to stations thousands of miles away. For example, I don't even get excited if I talk to a station in Australia or in Africa from my mobile HF radio. It's a lot of fun and very addictive.
Hope this helps.
Also, like mentioned in one of the previous posts, find a local club or an elmer. There is a "Field Day" even going on this weekend. Find out where your local group is setting up their station, drive up there and join them.
Most clubs will be happy to introduce you to the world of radios and will even let you operate their station. It's probably the biggest even in ham radio community. Check it out.