To the OP:
There is no reason that you should feel like owning nice things is inherently wrong and makes you "less Buddhist". It is true that if you pursue the path you will find yourself with no need for possessions that are extravagant, etc. because you will have realized that true happiness does not depend on such things and can in fact be hindered by them, but that is a long way off and the point of Buddhism is not to be a penniless beggar. The point is to attain freedom from suffering and share that freedom with as many sentient beings as possible. To that end, wealth can be helpful so long as one does not succumb to greed (Although it sounds like you're doing well here). It is wonderful that you generously dedicate a large portion of your income to philanthropy. Generosity is one of the six perfections of the bodhisattva (Akin to a Buddhist saint in this sense of the word), so you are well on your way.
The beauty of Buddhism is that it teaches us to be generous not just with money, but also with time, with smiles, with love. Most of all with loving-kindness, compassion and joy. Generosity in those respects is of the utmost value. So keep being generous and do not feel like your lifestyle precludes you from being a Buddhist.
Edit: You can start practicing right away with your philanthropic donations. When you donate, say this either out loud or silently three times...
I dedicate the merit of this offering to the liberation of all beings from suffering,
And to the efforts of the buddhas of the ten directions and the three times
May all beings be free of suffering and its causes,
May all beings never be separated from happiness and its causes,
May all beings experience endless joy and swift liberation
This is not a prayer in the theistic sense. The point of this exercise is to direct all of ones personal energy to the wholesome act being done and make very clear the intention for doing it. Eventually as you practice you will come to understand that when you utter words such as these, your personal energy is aligned with and amplified by innumerable sentient beings throughout the many realms who share your motivation and wishes. You will start to experience and tap into that incredible energy, and that will start to be the energy with which your generosity is dedicated.
This sort of giving, with dedication, is very meritorious and is sure to help you attain enlightenment and benefit countless beings.