Negotiating salary/benefits [Contractor to Full Time]

I’ve read several posts about people contract to hire roles asking the same question, however they have all been working as contractors for >6 months. I was originally hired through an agency to work for a company as a contractor for 12 months with a high likelihood of a full time offer prior to that year being completed. It’s been 2 years, with numerous false claims that the company would be able to extend a full time offer due to the nature of the industry and funding.

While I’m not holding my breath, there is a very good chance an offer will be made within the next month and I would like to have my plan for negotiating established for when that time comes.

I understand the company pays a premium to the contract agency for me, but that rate does not include benefits like healthcare, PTO, 401k, etc. Given the fact I have now worked for this company for 2 years without those benefits (even from the contract agency), I would like to use that as leverage for a higher salary, time served for PTO and educational benefits and potentially a starting bonus.

Do I have grounds to do so or am I setting myself up for disappointment?

Additional info: -position has had high turnover rate for contracted employees hired after me, leaving the department extremely short staffed for a growth based company. -2 years of experience with the company including establishing many of the procedures and tools currently used, understanding of expectations, policies, systems, etc. -highly praised for work ethic, performance and going above and beyond -track record of making myself available to learn and assist in new areas of the company