Hello agan Nicole -

With your sentences, my choice is: "Descubrí un sitio muy interesante en mi búsqueda para entender la palabra "echar de menos" y pensé que podría ser interesante para ti" (but without the tilde in 'ti'), because:

1.You cannot really use "buscando" as a noun;

2. If you write: "He descubierto ... y pensé" your two tenses do not match up - i.e., they are mutually inconsistent in this context - because the "pensé" [> "I thought", in the preterite] actually took place after the "He descubierto" [> "I have discovered" - this is in the present perfect or 'antepresente' - which [anomalously] makes this action sound more recent than the other one].

3. "Pensar" does not take a subjunctive, not even when it refers to something vague or unproved; (in any event, in your example here it is not at all 'nebulous' because you are using it in the sense of 'decide'). But there is actually no good way of explaining why 'pensar' and 'creer' do not take the subjunctive - [e.g., in Italian, they do !] ... However, if preceded by a 'no', then those two verbs do require a subjunctive.

4. "Puedas..." and "pudieras..." [... ser interesante] should not be in the second person ['tu'].... Compare your "Podría ..." [... ser interesante] - which is correctly in the 3rd person.

5. An important use of the conditional tense is representing the future from the viewpoint of something taking place in the past. So, for example if we start with the sentence "I think she will come" > "Pienso que ella vendrá" and then turn that into 'reported speech', we need to write: "Pensé que ella vendría" > "I thought she would come".... [In your first sentence, your 'podría' is correctly fulfilling that 'future in the past' function].

-.-.-.-

One last comment: "Descubrí un sitio muy interesante en mi búsqueda para entender la palabra "echar de menos" y pensé que te podría ser interesante" is probably better than the construction "... podría ser interesante para ti".

Cheers !

David M