Should I be content with poster paper or should I try again? A  research paper of mine has been accepted at an IEEE conference.  Although I submitted my best work as a research paper, my best was not  good enough and the reviewers threw it with the poster papers. So, it  will get published in the conference proceeding but will NOT get  uploaded to Xplore Library. 

Now  if I go with this, can I try submitting the same paper (as it won't be  online) to other IEEE conferences or reputed journals or do I have to  change it substantially before submitting to other publishers? This  would be a problem because I can not work on it any more without a  top-notch laboratory with chemical equipment; I already did what I  could with just a PC and a lot of time (I am an undergraduate student in a  developing country btw). 

Or keeping this in mind, should I simply  withdraw the paper and try elsewhere from scratch?
I would recommend to take the chance to visit the conference and discuss your poster content with others. This will give you good feedback and show you how your work is regarded in your field.