Archiving full page documents

I'm looking at the task of archiving around 15000-20000 pages of data. The data is in ASCII text files, but is a full page of formatted text. This data will need to be accessed up to 5 or 10 times a week and needs to be searchable and printable. I thought about creating a pdf file with all the contents but that is a lot of pages to search through when searching. It is not necessary to edit this data, it would actually be nice for it to be read-only. I'm just now starting to look into this and I would like some opinions on the different methods other professionals are using.

Thanks