Battery Replacement and Cold Cranking Amps

I have a Gill G25 battery in my Piper Arrow III (PA28R-201T). I
recently had a situation where I ran out of juice after 4 attempted
starts. While I am sure that I can improve my starting technique (I am
a newbie for this particular plane), I would like to have a bit more
power in my battery, especially in very cold conditions such as we have
up here in central Wisconsin.

An A&P told me recently that I am "stuck" with my G25 battery. He said
that he tested it and that it was "fine."

Based on a recent article in "Aviation Consumer", I learned that the G25
has only about 225 cold cranking amps. I noted that the G35S has 250
cold cranking amps.

(1) Is it true that I am stuck with a G25 battery and that NO OTHER
battery in the world can go in my plane? I find that a little hard to
believe.

(2) If there are other possibilities, can someone recommend one that has
better cold cranking amps that the G25?

Thanks in advance.

-Sami (N2057M, Piper Turbo Arrow III owner)