The short answer to your first question is "no," you do not have to give the long-time tenant the same 30-day notice as required for mobile home tenants. That notice under ORS 90.632 is only for mobile home tenants, not RVs. Since RVs are not "manufactured dwellings," you have some better options available.
Normally, I would recommend a 30-day, for-cause notice under ORS 90.392 requiring the tenant to repair his RV. Presumably your park has a rule requiring homes and RVs to be kept in good repair, which you would use as the basis for the notice. The 30-day notice would give the tenant 14 days to repair the RV or face termination of his tenancy at the end of the 30 days.
However, in this particular case it sounds like the travel trailer has been dilapidated for quite some time. Under ORS 90.412, you waived the right to evict the long-time tenant based on the condition of his RV by accepting rent for 3 or more months with knowledge of the condition of the RV. That is why I always recommend addressing problems with a notice as soon as the condition arises. (The rule is different for mobile homes - parks don't waive the right to evict even if the condition of the home has been longstanding).
Under the circumstances, your best option is to simply issue a 60-day, no-cause notice terminating the long-time tenancy. Presumably the tenant has been there for more than one year as a month to month tenant, which requires a 60-day notice.
The newer RV tenant with the messy space is a different story. If the condition of his space only became an issue recently, you could go with the 30-day, for-cause notice mentioned above. The basis of the notice would be your park rules requiring tenants to maintain their spaces, along with ORS 90.325 (1)(b) which requires tenants to keep their spaces "clean, sanitary and free from all accumulations" of debris and rubbish.
If the messy conditions have existed for 3 or more months, then you're only left with the no-cause eviction notice option. However, if the newer RV tenant has been there less than a year as a month to month tenant, the notice can be a 30-day, no-cause notice instead of a 60-day notice.