Does Vires acquirit eundo actually translate to "we gather strength as we go", or, "he gathers strength as he goes", or "he gathers strength along the way"? This is part of a possible tattoo design so obviously I need clarification. :)
The phrase could be translated literally as "he/she/it gathers strength by going". English and Latin have different grammatical structures available, so a direct translation isn't a good choice. Both "he gathers strength as he goes" and "he gathers strength along the way" are good translations.
The for acquirit is third person singular, but no pronoun is present. The subject can be understood as "he", "she", "it", or similar, but not "we". Originally the subject is "it" or "she".
Let us take a look at the phrase in it's original context:
Extemplo Libyae magnas it Fama per urbes—
Fama, malum qua non aliud velocius ullum;
mobilitate viget, viresque adquirit eundo,
parva metu primo, mox sese attollit in auras,
ingrediturque solo, et caput inter nubila condit…
(Vergilius, Aeneis IV.173–177)
If used in isolation, it makes sense to drop the enclitic -que which means "and". There are spelling differences in different editions. Some have viris instead of vires and some adquirit instead of acquirit. Your choice vires acquirit eundo represents a typical modern spelling choice of Latin.
The same site has an English translation by Theodore C. Williams, 1910:
Swift through the Libyan cities Rumor sped.
Rumor! What evil can surpass her speed?
In movement she grows mighty, and achieves
strength and dominion as she swifter flies…
This passage describes the personified Rumor, who grows bigger and stronger as she goes across the land from mouth to mouth. So, while in isolation your phrase can be taken legitimately as "he gathers strength along the way", it can also be interpreted as a shorthand for "rumors grow when they spread" or something similar.