If you want more range out of your mobile and base installations, you really have to look at antennas more than the radio or adding additional output power.
If you can't get a Wilson 1000 (or equivalent antenna) magmount or through the roof mount on the highest part of your vehicle, you will suffer in transmit and receive.
If you can't put a 1/4 wave or 5/8 wave base antenna up at least 36' feet at the home, you will suffer. A simple inverted V wire antenna will do a decent job for you, and offer minimum visual impact, but carefully check the SWR for proper loading, or you will suffer.
Your local terrain will be a factor too. Do you live in a hilly/mountainous region? or is it more flatland?
CB (hf) radio waves will bend over hills and generally give you more range than VHF/UHF signals, but you have to have the best possible installation you can afford (money-wise and neighbor-friendly-wise).
I am in southeastern Pennsylvania. The terrain is rolling hills, no big mountains. My home is only about 200 feet above sea level (check your altitude here
www.topozone.com )
At the base, I have a Galaxy DX 2547 CB base radio (about 15 watts out on sideband) feeding an Imax 2000 antenna, the feed point is 36 feet above the ground. I use no amplifier. I can easily get 20+ miles in all directions, usually more like 30 miles.
In the mobile, I run a Wilson 1000 through the roof mount (drilled the hole) and a Magnum 257. I can easily talk 10-20 miles with the 25 watts (SSB) output the 257 offers. Turning on a MagnaForce 300 does nothing substantial to add to that coverage locally, so I no longer run additional power in the mobile.
All my equipment is grounded, to reduce stray RF and to reduce noise in the receiver.
I have gotten a much bigger benefit from my radio installations since I spent the time and money on better antennas and grounding techniques, than I did with amplifiers. Also, those operators in my area who run amplifiers splatter the band pretty badly, making it hard for other operators to use the band. Courtesy is still a good thing in our society.
This amateur radio operator's website offers good suggestions for mobile installations, and has helped me immensely.
www.k0bg.com