Thanks for asking your question! I'm sorry to hear about your tax issue and I'm going to try my best to help you understand or resolve it.
Thank you for your question, and thanks for using JustAnswer.com. If you are going to form a tax exempt organization, you will form it under 501(c)(3) and if the status is granted, then your donations to the organization will be tax deductible.
501(c)(3) is usually only for Religious, Educational, Charitable, Scientific, Literary, Testing for Public Safety, to Foster National or International Amateur Sports Competition, or Prevention of Cruelty to Children or Animals Organizations.
Further, that 501(c)(10) might make sense, given the common purpose, as long as no life, health or other benefits are offered and that it WOULD be considered tax exempt if for certain Sec. 501(c)(3) purposes.
And that even a 501(c)(6) might make sense, and could still accomplish the purpose by establishing a charitable fund, contributions to which are deductible. Such a fund must itself meet the requirements of section 501(c)(3) and the related notice requirements of section 508(a)
To apply for this, file form 1023 with the IRS. More information can be found, HERE.
Please let me know if you need anything additional. Thanks for using JustAnswer.com and have a great day.
** Please take a moment to rate my response as "Excellent" so that I may be compensated for assisting you today. Please let me know if my assistance was anything less than "OK Service", as I am compensated based on whether or not I have assisted you with your issue. If you need further clarifications, PLEASE WAIT TO RATE MY ANSWER UNTIL AFTER RECEIVING FOLLOW UP FROM ME. If I receive anything less than OK Service, I do not get paid. Thank you for your kind understanding in this matter. If you have difficulties rating, then simply respond stating that you are having difficulties rating and thank me for my excellent, good, or ok service and we can get the rating applied by the site. This answer is not financial or legal advice, and must not be used as such. For financial and legal advice, please contact a local professional.*
You should be aware that your question, as with most tax questions, can never really be answered completely...addressing all the permutations; that is because of the many assumptions that have to be made I have done my best to determine what I think you are asking and answering it in the most direct and understandable manner possible. If, however, after reviewing the questions, you have any uncertainties or further questions, please do not hesitate to ask.