I think you are likely to find most people will be quite happy to endorse the Marauder. You may get some discussion on caliber. If you are intending to do some pesting, larger calibers do hit with more authority. A lot of people make the solid claim the .25 caliber "green mountain" barrel is the most accurate "factory barrel". This does not mean the other barrels are bad, it is just that the .25 caliber seems to edge out other barrels. I am not sure if it is simply that the ballistics tend to be better, the larger the pellet is. Some people have swapped out the .22 caliber barrel with the Marmot Militia brand barrel, and reported enhanced accuracy from the swap. Enough people have made the same claim, that I regard it as fact. If you want the greatest number of shots, and are planning on shooting at a maximum of 35 yards, the .177 barrel may be best for you. Just understand it is the caliber most affected by the wind, and tends to perform less well at longer ranges.
I actually started with a Benjamin Maximus single shot PCP, and it was a nice introduction to PCP. It was a .22 caliber PCP which only required 2000 pounds of pressure to fill. I selected it because I had an unreasonable concern about the difficulty to fill an airgun with a hand pump. It came as a "starter pack" which included the Benjamin hand pump. It worked well for the task. I ended up purchasing a .25 Marauder which I filled with the Benjamin hand pump, and although quite doable, it was a bit tiresome to fill by hand. Like others, I would endorse a better hand pump for air rifles which require a 3000 pound fill. I ended up getting a tank (mostly for my .357 bulldog).
Mods and more mods was the order of the day for me. When I got the Marauder I shot one full string through a chronograph. I wanted to confirm the gun worked, and what was the baseline performance of the air rifle. After that first recorded string, the Marauder was de-gassed and disassembled. The air-tube and especially where the hammer slid in the tube was de-burred and polished. The valve was replaced, a Huma regulator was added, a TSS adjustable spring assembly was installed along with a flyweight hammer, the port on the barrel was drilled out to .187 inches, a larger internal diameter port tube was installed, and the bolt was re-shaped to enhance air flow. It transformed the Marauder. Once tuned, it nearly doubled the number of good and accurate shots. It also increased the average shot power. The Marauder is an ideal platform to modify. There are several companies who make excellent parts for the Marauder. You can select components to go whichever direction pleases you. The most common tuning direction people go is the 40 (or more) shots at 40 foot pounds of energy (FPE), this is known as a 40/40 build. Some have modified the .177 to give crazy shot counts, others have modified them to shoot with 70 FPE for a limited number of shots (a 22 long rifle powder burner typically shoots with 100 FPE as a reference). Someone earlier mentioned a de-pinger, it is something added to the air tube to keep it from Ringing when you fire a shot, like a high pitched bell. If you add a Huma regulator, it eliminates ping. There is no need to get a Huma regulator AND a de-pinger.
And finally, the stock. I went with synthetic as the gun was going to be taken into the woods. For some reason, scratches on wood stocks make me unhappy. Scuffs on synthetic stocks do not offend me. Unless you win the stock-lottery, the woods stocks which come with Marauder tend to be a bit bland in terms of grain. If a stock is important to you, there are a few people in this forum who make custom stocks, but many will cost quite a bit. Also, Boyds stocks has an available multi-colored laminated stock they sell for the Marauder, some people have been happy with that product.